Sorry for staying off topic, but do you have glasses? If so, keep them clean and consider a better set of lenses.
Also, check the distance from the monitor. Decrease the resolution and move back a little. Try decreasing the brightness as well. Besides that, get more sleep.
I've been told eating carrots are good too. Try getting something healthy to eat, if you look at food once every 10 minutes, that's time away from the screen. Sure, not a lot, but it breaks the staring.
My ideas might seem stupid, but if you're on a lot, they can make a difference.
Besides my ideas, I'd go to a pharmacy and ask them what drops to use once you've tried my ideas.